Field of the Invention
The invention concerns a method for modification of a magnetic resonance actuation sequence with which a property of pulses to be activated or radiated is determined on the basis of the specification of a parameter of the magnetic resonance actuation sequence, as well as a magnetic resonance apparatus designed to implement such a method for modification of a magnetic resonance actuation sequence and a non-transitory, computer-readable data storage medium encoded with program code that causes such a method to be executed.
Description of the Prior Art
Magnetic resonance apparatuses are designed to generate images of patients, wherein the user of the magnetic resonance apparatus is able to enter various specifications that influence the images. The specifications are entered by the user before the start of the measurement. For example, the user can make inputs that ensure that the area to be scanned, i.e. the area to be depicted in images, covers the volume of interest of the patient and the images correspond to a desired contrast. To this end, the user can enter numerous specifications for the magnetic resonance apparatus (scanner thereof) that not only define the area to be scanned spatially but also relate to a magnetic resonance actuation sequence. Herein, the latter are termed sequence parameters.
Magnetic resonance actuation sequences are characterized by the temporal sequence of gradient pulses and radio-frequency (RF) pulses, as well as by their amplitude modulations and durations. Magnetic resonance actuation sequences are decisive in the determination of the contrast of images, but sequence parameters of a magnetic resonance actuation sequence are subject to numerous boundary conditions, which are established by the sequence parameters themselves or by further factors, such as the hardware of the magnetic resonance scanner or the choice of the spatial area to be scanned. The dependencies of the boundary conditions for a sequence parameter on other sequence parameters are derived from the principles of magnetic resonance tomography. For example, in a spin-echo sequence, the minimum repetition time is determined by the echo time.
The specification of a parameter by a user can have an effect on numerous other properties of the magnetic resonance actuation sequence, which, inter alia, have to be matched to the specified parameters and each other.